1. Field
One embodiment of the invention relates to a circuit board device provided with a radiator plate for cooling an electronic component and an electronic apparatus provided with the same.
2. Description of the Related Art
In recent years, there have been spread small-sized portable computers, called notebook personal computers or mobile computers. For higher portability, the main bodies of the computers of this type are being made smaller and smaller. At the same time, these computers are expected to have further improved performance and enhanced multifunctional properties.
In general, one such computer comprises a substantially rectangular flat main body and a display unit that is swingably attached to the body. The body contains a printed circuit board, on which a large number of electronic components are mounted, and a hard disc drive, an optical disc drive, etc. for use as information storage devices. In order to reduce the size of the computer, these components are arranged with high packing density in the computer body. Among electronic components that are provided in the body, moreover, a CPU and an IC chip are progressively enhanced in performance and generate much heat.
Accordingly, the computer of this type is provided with a cooling unit for cooling the interior of its body, e.g., the CPU. The cooling unit comprises a heat radiating member, such as a radiator plate or a heat sink duct formed of aluminum or some other highly heat-radiating metal. The heat radiating member is in contact with the CPU when it is mounted on the printed circuit board. The CPU is cooled in a manner such that heat transferred from the CPU to the heat radiating member is radiated into the computer body. The heat radiating member is elastically pressed against the CPU to cool the CPU securely.
The heat radiating member, as described in Jpn. Pat. Appln. KOKAI Publication No. 9-83165, for example, is usually mounted on the printed circuit board by being screwed to a stud on the board. The CPU, a heat generator, is mounted on one surface of the circuit board, and the heat radiating member is located on the same surface side of the board so as to overlap the CPU. The stud is tacked on the other surface of the printed circuit board by soldering. The heat radiating member is threadedly fixed by threading a fixing screw into the stud through the radiating member and the circuit board from the surface side of the circuit board.
As described above, however, the CPU and the heat radiating member are mounted on the one surface side of the printed circuit board with the stud projecting from the other surface of the board. In this state, the stud prevents other electronic components from being easily located and mounted in that region of the other surface of the circuit board on which the stud is set up. Thus, it is difficult to effectively utilize a space over the circuit board, which constitutes a hindrance to improvement of the packing density and reduction of the computer size.